Land degradation and declining soil fertility are major threats to agricultural productivity and food production, particularly in the drylands of sub-Saharan Africa, where land management practices, high fertiliser prices and water shortages contribute and exacerbate the problems. The World Resources Institute have previously calculated that to eradicate food insecurity we need to produce 69% more calories between 2006 and 2050, while at the same time protecting the world’s water, climate and ecosystems. A new report by the WRI entitled Improving Land and Water Management, instalment four of their Creating a Sustainable Food Future series, outlines some of the land and water management practices that can mitigate land degradation and increase agricultural output. They highlight four practices that are particularly promising, which along with raising yields and productivity can increase incomes, natural capital and resilience to climate change. These are:

Agroforestry – the integration of trees and shrubs onto farms

Conservation agriculture – the combination of reduced or no tillage, crop rotations and on-farm conservation of crop residues or cover crops

Rainwater harvesting – the use of on-farm systems such as bunds, pits and trenches, to collect rainfall and prevent water loss from soils

Integrated soil fertility management – the incorporation of prudent and targeted use of fertiliser with organic alternatives such as manure, compost, leaf litter, crop residues and phosphate rock

The report provides evidence of the impacts these farming practices can have, for example, the combination of conservation agriculture and crop rotations has resulted in 50% higher yields of maize in Zambia. These practices can be combined with each other as well as with more conventional technologies e.g. microdosing of fertilisers.

Implementing and combining these four techniques at scale will require much coordination between different users of the landscape, warranting an integrated landscape approach that acknowledges and plans for multiple land uses. Adoption of these practices is currently low and the main barriers to successful scaling include poor knowledge dissemination, weak land tenure systems and poor coverage of extension services. The potential of these improved land and water management practices has been calculated: if implemented on some 75 million hectares of cropland, with an expected increase in yields of 50%, farmers would produce 22 million tons more food each year, equating to an extra 615 kilocalories per person per day for 285 million people living in Africa’s drylands. [Read more…]

The Soil Atlas of Africa aims to increase African countries’ understanding of the diversity of soils found on the continent, the importance in managing this key resource and to aid governments in strategically planning land use and investments in agriculture and urban development.

The project started four years ago and is a collaboration between experts at the European commission, the AU and the UN Food and Agriculture Organisation (FAO). Already the map has helped identify areas, in central Africa, some parts of West Africa, and southern Africa where soil is particularly fertile. Experts working on the project also hope it will strengthen government support for national soil bureaus and for training users of the Atlas at the regional level.

Declining soil fertility and soil loss is a significant problem in Africa. Nearly 3.3% of agricultural GDP is lost in sub-Saharan Africa each year due to soil and nutrient loss while more than 75% of total land in the area has degraded or highly degraded soil. The Atlas will help to identify trouble zones so that plans for the sustainable use of soil can be put in place.

December 5th was a day dedicated to an often overlooked resource that underpins food production on the planet, soil. In One Billion Hungry, chapter 13 lays out the threats to soil and ways in which soil degradation, depletion and fertility loss can be tackled.

On the fiftieth anniversary of Rachel Carson’s Silent Spring, Guardian writer Leo Hickman, opened up discussion about the book’s impact on the world. The comments that follow the article raise several questions:

While synthetic pesticides are manufactured to be more targeted and less harmful to the environment they are also used prolifically and use is growing. So in terms of the chemicals we pump into the environment are we better off now or back then, in 1962 when the book was first published?

This leads to a second question: given our knowledge of the harm pesticides and other chemicals can have on the environment and human health, for example the recent evidence of the link between pesticides and declines in bee numbers, and, in some cases, their limited time period of effectiveness on pests, are we even more irresponsible to be continuing to use such products in this day and age?

A clear message from the book is that if the human population itself is to be sustainable we must co-exist with nature in the same way that environmentalism and economics must learn to co-exist or combine. But are we any nearer to reaching this and can the two fields find the middle ground?

Finally, how can two goals seemingly at odds with one another – feeding the world’s chronically hungry, 98% of which are in developing countries and 80% of which are smallholder farmers often facing pest, disease and soil fertility challenges, and ensuring the planet’s sustainability – be resolved?

We’d love to hear your thoughts on these questions, to continue the discussion and to ensure we make progress within the next 50 years.

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One Billion Hungry: Can We Feed the World?

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About this site

This blog is run by Agriculture for Impact (A4I), an independent advocacy initiative led by Professor Sir Gordon Conway, author of the book One Billion Hungry: Can We Feed the World?

A4I aims to enable better European government support for productive, sustainable, equitable and resilient agricultural development in sub-Saharan Africa, focusing in particular on the needs of smallholder farmers.

Agriculture for Impact also convenes the Montpellier Panel, a group of European and African experts in the fields of agriculture, trade, ecology and global development.

It is based at Imperial College London and is supported through the Bill & Melinda Gates Foundation